1、September 2016 English price group 12No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 67.100.10!%ZlO“2557344www.din.
2、deDIN EN ISO 8968-4Milk and milk products Determination of nitrogen content Part 4: Determination of protein and non-protein nitrogen content and true protein content calculation (Reference method) (ISO 8968-4:2016);English version EN ISO 8968-4:2016,English translation of DIN EN ISO 8968-4:2016-09M
3、ilch und Milcherzeugnisse Bestimmung des Stickstoffgehaltes Teil 4: Bestimmung des Proteinstickstoff-Gehaltes und des Nichtproteinstickstoff-Gehaltes und Berechnung des tatschlichen Proteingehaltes (Referenzverfahren) (ISO 8968-4:2016);Englische Fassung EN ISO 8968-4:2016,Englische bersetzung von DI
4、N EN ISO 8968-4:2016-09Lait et produits laitiers Dtermination de la teneur en azote Partie 4: Dtermination de la teneur en azote protique et non protique et calcul de la teneuren protines vraies (Mthode de rfrence) (ISO 8968-4:2016);Version anglaise EN ISO 8968-4:2016,Traduction anglaise de DIN EN I
5、SO 8968-4:2016-09SupersedesDIN EN ISO 8968-4:2002-06 andDIN EN ISO 8968-5:2002-06www.beuth.deDocument comprises 21 pagesDTranslation by DIN-Sprachendienst.In case of doubt, the German-language original shall be considered authoritative.08.16 DIN EN ISO 8968-4:2016-09 2 A comma is used as the decimal
6、 marker. National foreword This document (EN ISO 8968-4:2016) has been prepared by Technical Committee ISO/TC 34 “Food products (Secretariat: AFNOR, France), Subcommittee SC 5 “Milk and milk products (Secretariat: NEN, Netherlands) in collaboration with Technical Committee CEN/TC 302 “Milk and milk
7、products Methods of sampling and analysis” (Secretariat: NEN, Netherlands). The responsible German body involved in its preparation was DIN-Normenausschuss Lebensmittel und landwirtschaftliche Produkte (Food and Agricultural Products Standards Committee), Working Committee NA 057-05-13 AA Milch und
8、Milcherzeugnisse Probenahme- und Untersuchungsverfahren. The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 707 DIN EN ISO 707 ISO 5725-1 DIN ISO 5725-1 ISO 5725-2 DIN ISO 5725-2 ISO 8968-1 DIN EN ISO 8968-1 Amendments This standard differ
9、s from DIN EN ISO 8968-4:2002-06 and DIN EN ISO 8968-5:2002-06 as follows: a) the title of the standard has been enlarged; b) the scope has been extended and is described in greater detail as a result of the consolidation of Parts 4 and 5 of standards series 8968; c) precision data have been revised
10、; d) Informative Annex A with the results of a collaborative study has been added; e) the standard has been technically and editorially revised and brought in line with current rules of presentation. Previous editions DIN EN ISO 8968-4: 2002-06 DIN EN ISO 8968-5: 2002-06 DIN EN ISO 8968-4:2016-09 3
11、National Annex NA (informative) Bibliography DIN EN ISO 707, Milk and milk products Guidance on sampling DIN EN ISO 8968-1, Milk and milk products Determination of nitrogen content Part 1: Kjeldahl principle and crude protein calculation DIN ISO 5725-1, Accuracy (trueness and precision) of measureme
12、nt methods and results Part 1: General principles and definitions DIN ISO 5725-2, Accuracy (trueness and precision) of measurement methods and results Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method DIN EN ISO 8968-4:2016-09 4 This pag
13、e is intentionally blank EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 8968-4 April 2016 ICS 67.100.10 Supersedes EN ISO 8968-4:2001, EN ISO 8968-5:2001English Version Milk and milk products - Determination of nitrogen content - Part 4: Determination of protein and non-protein nitrogen co
14、ntent and true protein content calculation (Reference method) (ISO 8968-4:2016) Lait et produits laitiers - Dtermination de la teneur en azote - Partie 4: Dtermination de la teneur en azote protique et non protique et calcul de la teneur en protines vraies (Mthode de rfrence)(ISO 8968-4:2016) Milch
15、und Milcherzeugnisse - Bestimmung des Stickstoffgehaltes - Teil 4: Bestimmung des Proteinstickstoff-Gehaltes und des Nichtproteinstickstoff-Gehaltes und Berechnung des tatschlichen Proteingehaltes (Referenzverfahren) (ISO 8968-4:2016) This European Standard was approved by CEN on 19 March 2016. CEN
16、members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on appli
17、cation to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Man
18、agement Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latv
19、ia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marn
20、ix 17, B-1000 Brussels 2016 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 8968-4:2016 EForewords .51 Scope . 72 Normative references 73 Terms and definitions . 74 Principle 74.1 Indirect protein nitrogen .74.2 Direct protein
21、nitrogen 85 Reagents 85.1 General . 85.2 Trichloroacetic acid (CCl3COOH) solution 85.3 Hydrochloric acid standard volumetric solution . 86 Apparatus . 87 Sampling 98 Preparation of test sample . 99 Procedure Direct protein nitrogen approach . 99.1 Test portion 99.2 Determination . 99.2.1 Precipitati
22、on and filtration . 99.2.2 Preparation of the precipitate . 109.2.3 Digestion and distillation 109.2.4 Titration 109.3 Blank test 109.4 Calculation and expression of results. 109.4.1 Calculation of protein nitrogen content 109.4.2 Expression of results .119.4.3 Calculation of true protein content .
23、119.4.4 Expression of the true protein content results . 1110 Procedure Indirect protein nitrogen approach . 1210.1 Nitrogen determination . 1210.2 Non-protein nitrogen determination 1210.2.1 Test portion . 1210.2.2 Precipitation and filtration 1210.2.3 Preparation of the filtrate 1210.2.4 Digestion
24、 and distillation 1210.2.5 Titration 1210.3 Blank test 1210.4 Calculation and expression of results. 1310.4.1 Calculation of non-protein nitrogen content 1310.4.2 Calculation of protein nitrogen content 1310.4.3 Expression of results . 1410.4.4 Calculation of true protein content . 1410.4.5 Expressi
25、on of the true protein content results . 1411 Precision 1411.1 Interlaboratory test 1411.2 Repeatability 1411.3 Reproducibility 1412 Test report 15Contents PageEuropean forewords 4EN ISO 8968-4:2016 (E) DIN EN ISO 8968-4:2016-09 2 Bibliography .17Annex A (informative) Results of a collaborative stud
26、y Estimation of precision data of direct and indirect methods for the true protein determination .16EN ISO 8968-4:2016 (E) DIN EN ISO 8968-4:2016-09 3 European foreword This document (EN ISO 8968-4:2016) has been prepared by Technical Committee ISO/TC 34 “Food products“ in collaboration with Technic
27、al Committee CEN/TC 278 “Milk and milk products - Methods of sampling and analysis” the secretariat of which is held by NEN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by October 2016, and confl
28、icting national standards shall be withdrawn at the latest by October 2016. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This docum
29、ent supersedes EN ISO 8968-4:2001 and EN ISO 8968-5:2001. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, F
30、inland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text o
31、f ISO 8968-4:2016 has been approved by CEN as EN ISO 8968-4:2016 without any modification. EN ISO 8968-4:2016 (E) DIN EN ISO 8968-4:2016-09 4 ForewordsISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of prep
32、aring International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in
33、liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC
34、Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility tha
35、t some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent de
36、clarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information
37、 about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products and the International Dairy Federation (I
38、DF). It is being published jointly by ISO and IDF.This second edition of ISO 8968-4|IDF 20-4 cancels and replaces ISO 8968-4|IDF 20-4:2001 and ISO 8968-5|IDF 20-5:2001, which have been technically revised.ISO 8968|IDF 20 consists of the following parts, under the general title Milk and milk products
39、 Determination of nitrogen content: Part 1: Kjeldahl principle and crude protein calculation Part 3: Block-digestion method (Semi-micro rapid routine method)1) Part 4: Determination of protein and non-protein nitrogen content and true protein content calculation (Reference method)1) It is intended t
40、hat upon revision, the main element of the title of ISO 8968-3|IDF 20-3 (i.e. “Milk”) will be aligned with the main element of the titles of ISO 8968-1|IDF 20-1 and ISO 8968-4|IDF 20-4.EN ISO 8968-4:2016 (E) DIN EN ISO 8968-4:2016-09 5 IDF (the International Dairy Federation) is a non-profit private
41、 sector organization representing the interests of various stakeholders in dairying at the global level. IDF members are organized in National Committees, which are national associations composed of representatives of dairy-related national interest groups including dairy farmers, dairy processing i
42、ndustry, dairy suppliers, academics and governments/food control authorities.ISO and IDF collaborate closely on all matters of standardization relating to methods of analysis and sampling for milk and milk products. Since 2001, ISO and IDF jointly publish their International Standards using the logo
43、s and reference numbers of both organizations.Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. IDF shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the deve
44、lopment of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute and endorsementISO 8968-4|IDF 20-4 was prepared by the I
45、DF Standing Committee on Analytical methods for composition and ISO Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products.The work was carried out by the IDF/ISO Project Group (C13) of the Standing Committee on Analytical methods for composition under the aegis of i
46、ts project leaders, D. Barbano (US) and P. Trossat (FR).This ISO|IDF International Standard cancels and replaces ISO 8968-4|IDF 20-4:2001 and ISO 8968-5|IDF 20-5:2001, which have been technically revised.ISO 8968|IDF 20 consists of the following parts, under the general title Milk and milk products
47、Determination of nitrogen content: Part 1: Kjeldahl principle and crude protein calculation Part 3: Block-digestion method (Semi-micro rapid routine method) Part 4: Determination of protein and non-protein nitrogen content and true protein content calculation (Reference method)EN ISO 8968-4:2016 (E)
48、 DIN EN ISO 8968-4:2016-09 6 WARNING The use of this part of ISO 8968|IDF 20 can involve the use of hazardous materials, operations and equipment. This part of ISO 8968|IDF 20 does not purport to address all the safety risks associated with its use. It is the responsibility of the user of this part of ISO 8968|IDF 20 to establish appropriate s
